if (document.images) {
var navi_1 = new Image()
navi_1.src = "images/st_navi01.gif";
var navi_1_2 = new Image()
navi_1_2.src = "images/st_navi01_on.gif";

var navi_2 = new Image()
navi_2.src = "images/st_navi02.gif";
var navi_2_2 = new Image()
navi_2_2.src = "images/st_navi02_on.gif";

var navi_3 = new Image()
navi_3.src = "images/st_navi03.gif";
var navi_3_2 = new Image()
navi_3_2.src = "images/st_navi03_on.gif";

}

function act(imgName) {
	if (document.images)
	document[imgName].src = eval(imgName + '_2.src')
}

function inact(imgName) {
	if (document.images)
	document[imgName].src = eval(imgName + '.src')
}